1. Field of the Invention
The present invention relates to a changeable display device having an array of several display elements, each display element having two different display surfaces.
2. Description of the Prior Art
Many business establishments utilize signs to advertise prices of certain key items. Gasoline filling stations, for example, generally advertise the price of gasoline, cigarettes or other products in this manner. Hotels, motels, automobile dealerships, and other roadside businesses similarly display prices or other information to the public. Because the prices or other information may vary with time, it is necessary that the sign be changeable to reflect these changes.
Some of the existing changeable signs provide for the numbers or letters to be removable from the basic structure of the sign. The sign is changed by removing the individual numbers or letters and replacing them with others. The individual characters are attached to the sign in a variety of ways. These signs, however, have at least three primary disadvantages. First, the user of the sign is required to select and store the proper combination of numbers and letters to enable him to display the desired variety of messages. The user is therefore burdened with the expense of maintaining the selection of display characters. Second, the display characters for some signs may be required to be five or more feet tall, and characters of this size are particularly unwieldy and susceptible to being lost or damaged. In addition, one or more characters in a particular display may be removed or otherwise become detached from the sign, thereby making the sign display incomplete.
It is therefore desirable to have a changeable display device which does not incorporate detachable elements. This has been accomplished by providing display devices which include an array of regularly-shaped display elements. Each display element typically has at least two sides of contrasting colors, and an equal number of display positions in which one of the sides is viewable from the front of the device. Each individual number or letter in the display is formed by positioning the appropriate arrangement of display elements to form that number or letter.
The primary requirements for a changeable display device of the latter description are that the display device be of simple and durable construction, and that the display positions of the display elements be quickly and conveniently changed. Preferably, the position changes should be possible to perform at a position remote from the sign, as where the sign is positioned high above the ground. In addition, it is necessary that the display device provide appropriate means for maintaining each of the display elements in the appropriate display position.
In U.S. Pat. No. 1,679,520, issued to Giroux on Aug. 7, 1928, there is shown a changeable sign which includes an array of flat display panels. Each display element is maintained in position by resilient clips which engage the adjacent panels. The Giroux device, however, does not provide a means for locking the display panels in position, as would be appropriate for a sign which is used outdoors. The display panels therefore may be easily manipulated by anyone having access to the sign in order to alter the intended message. In addition, a large sign, according to the Giroux patent, would comprise relatively large display panels which could be affected by wind and other natural phenomena to cause the individual panels to become disengaged.
A second locking or detent means is disclosed in U.S. Pat. No. 3,410,011, issued to Bowman, on Nov. 12, 1968. The Bowman device includes an array of three-sided elements. The display elements are maintained in display position by a resilient, foam material which is positioned to engage the corner of each display element opposite the visible side. Alternatively, the Bowman device includes a rigid plastic backing plate which has detent tabs for engaging the corners. The Bowman device, however, does not provide a means for preventing the display elements from being manipulated by a person having access to the sign. In addition, the utilization of three-sided display elements as in the Bowman device results in a display device which has increased construction costs and difficulties.
In U.S. Pat. No. 1,004,810 issued to Newell on Oct. 3, 1911, there is disclosed a transmutable display device having a two-dimensional array of display elements. Each of the display elements has generally two sides, the first being flat and the second being curved. The area between the two surfaces is open, and the display elements are suspended on a framework which includes rods which pass through the opening between the two surfaces. In one display position, the associated rod is received along the juncture between the flat and round surfaces with the flat surface being viewable from the front of the display device. To obtain the other display surface, the display element is rotated about the associated rod and allowed to slide downwardly so that the rod is then received at the opposite juncture of the flat and rounded surfaces. In this position, the rounded surface is viewable from the front of the display device. As with the prior art devices previously described, the Newell display device doesn't provide for securing the display elements in a particular display position, and does not permit the display positions of the display elements to be changed from a position remote from the display device.
Another display device utilizing an array of display elements having sides of contrasting colors is disclosed in U.S. Pat. No. 532,032 issued to Dalumi on Jan. 8, 1895. Each of the display elements is hingedly attached to the back wall of the sign, and includes a spring member which normally holds the display element in the down position. A cable is attached to each of the display elements to enable them to be rotated upwardly from a position remote from the sign. In one position, the exposed side of the display element and the surrounding back wall are the same color. When rotated to the other display position, the newly-exposed side of the display element and the potion of the back wall previously covered by the display element (when in the down position), have the same color, and that color contrasts with the color of the surrounding back wall. According to the Dalumi patent, the method for selectively positioning each of the display elements in one or the other display positions is initiated by first rotating all of the display elements to the up position. This is accomplished by rotating a drum to which each of the cables is attached. When in the up position, the display elements are engaged by a catch. An electromagnet is positioned above each of the catches and when activated, causes the catch to move away from the display element to permit it to rotate to the down position. Selection of those display elements which are desired to be in the down position is therefore accomplished by activating the proper electromagnets, after all of the display elements have been first moved to the up position. The Dalumi device does solve several of the problems associated with changeable display devices, but it does not provide a simple and inexpensive method for selectively positioning the various display elements.